A wide variety of different types of cables are utilized to transmit signals. For example, communication cables, such as twisted pair and optical fiber cables, are utilized to transmit data signals. Many cables incorporate components that are formed from polymeric materials. For example, optical fiber cables often incorporate polymeric buffer tubes, microtubes, core inserts, etc. As another example, twisted pair cables may incorporate polymeric separators or fillers. Other cable components, such as core wraps, can also be formed from polymeric materials.
It is often desirable for certain types of polymeric cable components (e.g., buffer tubes, etc.) to be formed from materials that have a relatively high Young's modulus. A material with a high Young's modulus will generally have a relatively high tensile strength and compressive resistance capability, thereby helping to protect other cable components (e.g., optical fibers, etc.) in the event a cable is twisted, stretched, or compressed. Additionally, it is often desirable to utilize materials that have a relatively low thermal expansion coefficient, thereby limiting shrinkage or expansion caused by temperature changes that can lead to damage of other cable components.
Traditionally, prior art polymeric cable components have been made from materials such as polybutylene terephthalate (“PBT”), polycarbonate (“PC”), a layered combination of PBT and PC, or a polyamide such as Nylon 12. Although each of these materials has a relatively high Young's modulus and a relatively low thermal expansion coefficient, these materials are often more costly, less flexible, more moisture sensitive, and more difficult to process than other polymeric materials, such as polypropylene (“PP”), polyethylene (“PE”), and co-polymers thereof.
More recently, cable components have been formed from PP-PE copolymers that have been nucleated with talc, clay, silica, or another inorganic material as a nucleating agent. The nucleation of the copolymers provides improved compression-tension resistance and shrinkage performance over non-nucleated materials, thereby allowing the PP-PE copolymers to be used instead of PBT and similar more costly materials. However, there is an opportunity for improved polymeric materials that provide relatively greater mechanical and temperature performance relative to materials nucleated with talc or a similar inorganic material. In particular, there is an opportunity to form improved cable components constructed from one or more polymeric materials that include one or more thermoplastic elastomers as nucleating agents and/or impact modifiers.